Yield of winter wheat grown under zero and conventional tillage on different soil types.

In three-year field trials, conducted in West Poland, the growth and development of winter wheat grown under zero tillage (ZT) and conventional tillage (CT) methods on four soils were investigated. The soils were different mainly in grain fraction distribution and content of organic matter. The tested soils were sandy loam (SL), loamy sand (LS-1, LS-2) and sand (S). In GPS-fixed sites, in ZT and CT fields, yield of aerial part biomass in four growth stages: stem elongation, second node, and heading and inflorescence phases, was compared. In addition, yields of grain and straw were tested. On medium and coarse textured soils (SL, LS-1, LS-2), more biomass was produced by wheat under CT than ZT, but on very coarse textured soil (S), the biomass yields obtained from wheat growing under both soil tillage methods were identical. On medium textured soils and on coarse textured (LS-1) soil, wheat under CT contained more N and P as well as much more Ca and Mg in tissues than under ZT. In contrast, on the other coarse textured (LS-2) soil and on very coarse textured soil, wheat plants under ZT were generally characterized by identical or slightly higher nutrient content than plants under CT. Despite periodic fluctuations in biomass yields between ZT and CT for particular growth stages of wheat, the yields of grain and straw were the same for both soil tillage methods, irrespective of the soil type.